Answer:
?
Explanation:
A student carries out a flame test on an unknown solid. a red flame is seen. the student concludes that the solid is lithium carbonate. explain why this conclusion is not justified
Why must the spot applied to a TLC plate be above the level of the developing solvent? What problem will ensue if the level of the developing liquid is higher than the applied spot in a TLC analysis?
Answer:
See explanation
Explanation:
If the spot in TLC is below the solvent front, it will be observed that the spot, instead of being separated by the solvent as expected, will just dissolve away in the solvent and zero actual separation of the mixture is achieved.
If the solute is dissolved away instead of being separated by the solvent, then the experiment fails because no actual separation of the mixture is achieved.
Hence, in TLC, the spot must be applied above the solvent front so that the capillary movement of the solvent through the plate can lead to the eventual separation of the components of the mixture since the various components of the mixture will travel at different speeds through the plate.
Also, if the solvent is above the spot, the solvent may evaporate selectively from the points above the spot while separation is ongoing.
Calculate the amount of heat associated with cooling a 350.0 g aluminum bar from 70.0 oC to 25.0 oC. The specific heat of aluminum is 0.897 J/g oC. (–14,127.75 J)
Explanation:
[tex]q = 350 \times0.897 \times (70 - 25) \\ q = 14127.75[/tex]
Drag the tiles to the correct boxes. Not all tiles will be used.
Match each Sl unit to the quantity it measures.
Answer:
1) Length - Meter
2) Mass - Pound
3) Time - Minute
Please Mark This As Brainliest!
f(x) = -x2+x+6
x
-2
a
-1
4
0
b
1
6
2
c с
do
11 11 11
Cross primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium. All the vascular tissues within a particular plant together constitute the vascular tissue system of that plant.
Which expression gives the standard enthalpy
change of formation for methanol?
Answer:
25
Explanation:
bec
Disadvantages of modern periodic table?
Answer:
It has its elements with mass numbers phrased in many decimal places, it requires one to round off to get the actual value.
The atomic numbers of some elements such as Protonium were just guessed.
When Logan opens a new bottle of carbonated beverage, the sudden release of pressure causes the beverage to bubble up and overflow. What could Logan do in the future to prevent the next bottle from overflowing when he opens it
Answer:
When Logan opens a new bottle of carbonated beverage, the sudden release of pressure causes the beverage to bubble up and overflow. What could Logan do in the future to prevent the next bottle from overflowing when he opens it.
Explanation:
This is an application of Boyle's law.
According to Boyle's law:
the volume of a fixed amount of gas is inversely proportional to its pressure at a constant temperature.
[tex]V \alpha \frac{1}{P}[/tex]
So, if pressure reduces all of a sudden, the volume increases and this causes an overflow of the beverage from the bottle.
To avoid this situation, the pressure inside the bottle should not be released at once. The bottle cap should be opened slowly in such a way that opens a little and then close again open a little and then close like that many times if we do, then pressure inside the bottle goes slowly then, the volume will not increase all of a sudden.
Consider the reaction between an alcohol and tosyl chloride, followed by a nucleophile. Write the condensed formula of the expected main organic product.
CH3CH2CH2OH---------- 2.CI 1.TsCl,pyridine__________
Answer:
Consider the reaction between an alcohol and tosyl chloride, followed by a nucleophile. Write the condensed formula of the expected main organic product.
CH3CH2CH2OH---------- 2.CI 1.TsCl,pyridine__________
Explanation:
Given alcohol is propanol.
When it reacts with TsCl, the hydrogen in -OH group is replaced with tosyl group.
Pyridine is a weak base and it neutralizes the HCl (acid) formed during the reaction.
The reaction is shown below:
mostly located on the bottom of the leaf, open close the stomata
Answer:
Guard cells. The guard cells also contain chloroplast.
select the two atomic models that belong to the same element !
Answer:
The second and the third atomic model.
Explanation:
An element is identified by the no. of protons in the said element. Proton number cannot be changed. Both second and third atomic model have 5 protons, so they are of the same element.
I need help please ASAP
How do scientists test their ideas
..........................
In which two ways does a balanced chemical equation model the law of
conservation of mass?
Answer:Matter cannot be created or destroyed in chemical reactions. This is the law of conservation of mass. In every chemical reaction, the same mass of matter must end up in the products as started in the reactants. Balanced chemical equations show that mass is conserved in chemical reactions
Explanation:
sorry it is late but hope it helps!(o゜▽゜)o☆
all first level consumers are carnivore: True or false?
The compound sodium hydrogen sulfate is a strong electrolyte. Write the reaction when solid sodium hydrogen sulfate is put into water:
Answer:
NaHSO₄(s) --H₂O--> Na⁺(aq) + HSO₄⁻(aq)
Explanation:
Sodium hydrogen sulfate is a strong electrolyte, that is, when dissolved in water it completely dissociates into the cation sodium and the anion hydrogen sulfate. The corresponding chemical equation is:
NaHSO₄(s) --H₂O--> Na⁺(aq) + HSO₄⁻(aq)
(a) Describe the process by which Nitrogen is obtained from air on a large scale
The element nitrogen exists as a gas and is obtained from air on a large scale by fractional distillation of air.
What is an element?An element is defined as a substance which cannot be broken down further into any other substance. Each element is made up of its own type of atom. Due to this reason all elements are different from one another.
Elements can be classified as metals and non-metals. Metals are shiny and conduct electricity and are all solids at room temperature except mercury. Non-metals do not conduct electricity and are mostly gases at room temperature except carbon and sulfur.
The number of protons in the nucleus is the defining property of an element and is related to the atomic number.All atoms with same atomic number are atoms of same element.
Learn more about element,here:
https://brainly.com/question/14347616
#SPJ2
A 66.4 gram sample of Ba(ClO4)2 3 H2O was heated thoroughly in a porcelain crucible, until its weight remained constant. After heating, how many grams of the anhydrous compound remained?
Answer:
57.2 g
Explanation:
First we convert 66.4 grams of Ba(ClO₄)₂·3H₂O into moles, using its molar mass:
Molar mass of Ba(ClO₄)₂·3H₂O = Molar mass of Ba(ClO₄)₂ + (Molar Mass of H₂O)*3Molar mass of Ba(ClO₄)₂·3H₂O = 390.23 g/mol66.4 g ÷ 390.23 g/mol = 0.170 mol Ba(ClO₄)₂·3H₂O0.170 moles of Ba(ClO₄)₂·3H₂O would produce 0.170 moles of 0.170 moles of Ba(ClO₄)₂. Meaning we now convert 0.170 moles of Ba(ClO₄)₂ into grams, using the molar mass of Ba(ClO₄)₂:
0.170 mol * 336.23 g/mol = 57.2 gIn the reaction below, what is the limiting reactant when 1.24 moles NH3 of reacts with 1.79 moles of NO?
4NH_3 + 6NO (right arrow) 5N_2 + 6H_2O
1. NO
2. H_2O
3. NH_3
4. N_2
Answer:
Option 1. NO
Explanation:
The balanced equation for the reaction is given below below:
4NH₃ + 6NO —> 5N₂ + 6H₂O
From the balanced equation above,
4 moles of NH₃ reacted with 6 moles of NO.
Finally, we shall determine the limiting reactant. This can be obtained as follow:
From the balanced equation above,
4 moles of NH₃ reacted with 6 moles of NO.
Therefore, 1.24 moles of NH₃ will react with = (1.24 × 6)/4 = 1.86 moles of NO
From the calculation made above, we can see that a higher amount of NO (i.e 1.86 moles) than what was given (i.e 1.79 moles) is needed to react completely with 1.24 moles of NH₃.
Therefore, NO is the limiting reactant and NH₃ is the excess reactant.
Thus, the 1st option gives the correct answer to the question
Answer:
1. NO .
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to identify the limiting reactant by simply calculating the moles of any product, say N2, via the moles of each reactant and including the corresponding mole ratio (4:5 and 6:5):
[tex]1.24molNH_3*\frac{5molN_2}{4molNH_3}=1.55molN_2 \\\\1.79molNO*\frac{5molN_2}{6molNO}=1.50molN_2[/tex]
Thus, since NO yields the fewest moles of N2 product, we infer it is the limiting reactant.
Regards!
An elephant walks north from a watering hole for 1 mile. The elephant
encounters a hill and turns east. The elephant continues to walk east until it
reaches a tree. It stays near the tree for 1 hour before continuing on to a
grassy field. Which point of reference should be used to describe the
elephant's motion?
A. The grassy area
B. The hill
STA
Tel
C. The tree
D. The watering hole
Answer:
i think its c because thats when the direction changes and you dont know where he went.
Explanation:
28) Which of the following is true about the modern model of the atom?
A) Electrons orbit the nucleus in shells at fixed distances
B) Protons, neutrons, and electrons are located in the nucleus.
C)Atoms are hard, indivisible spheres.
D)A positive nucleus is surrounded by negative electrons.
Answer:
A) Electrons orbit the nucleus in shells at fixed distances
Answer:
the answer is A
Explanation:
Draw the curved arrows showing a proton transfer reaction, and draw the products of that proton transfer. Do not include the Li counterion, and lone pairs are not required in the products.
Answer:
Draw the curved arrows showing a proton transfer reaction, and draw the products of that proton transfer. Do not include the Li counterion, and lone pairs are not required in the products and the question is hsown below:
Explanation:
The proton from water is abstracted by butyl carbanion and hydroxide ion is formed from water.
The reaction is shown below in the attachment.
Which scientist developed the first model of the atom that showed the structure of the inside of an atom
Answer:
Which scientist developed the first model of the atom that showed the structure of the inside of an atom
Ernest Rutherford
how many molecules are there in 75.0 grams of phosphorus trichloride plzz helpp
Answer:
Explanation:
55
20ml of water is mixed with 40gm of fine powder. Calculate the concentration of the solution obtained.
Answer:
[tex]\%m=66.7\%[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to calculate the concentration of the solution obtained, by knowing 20 mL of water are the same to 20 g and therefore the mass of the solution is 40g+20g=60g.
Next, we apply the following equation to obtain the required concentration:
[tex]\%m=\frac{40g}{60g} *100\%\\\\\%m=66.7\%[/tex]
Regards!
for each 20 grams of glucose made by the plant, calculate the mass of water used
Answer: 6
Explanation:
You would need 6
When a metal cation forms an octahedral complex the ligands approach directly along the x, y, and z axes. The two d orbitals with lobes along the axes will experience a _____ repulsion than the three d orbitals with lobes between the axes. The d orbitals will be split into two groups; the higher energy group has _____ orbitals and the lower energy group has _____ orbitals.
Answer:
greater, two, three
Explanation:
Cations are positively charged ions. In an octahedral complex, the d orbitals undergo greater repulsion and split into 2 high, and 3, low energy groups.
What are octahedral complexes?An octahedral complex is a molecular geometry of a compound in which the six atoms are aligned in symmetry around the central metal atom.
The molecule has eight faces and hence is called octa. The two d orbitals present in the structure experience greater repulsive force compared to the three orbitals of d orbit.
Therefore, the d orbit of the molecule has two high-energy orbitals while having three lower energy molecules.
Learn more metal cation here:
https://brainly.com/question/14225650
Why all mushrooms cannot be eaten?
Explanation:
The toxins present are secondary metabolites produced by the fungus. Mushroom poisoning is usually the result of ingestion of wild mushrooms after misidentification of a toxic mushroom as an edible species. ... The safety of eating wild mushrooms may depend on methods of preparation for cooking.
True or false: this reaction is balanced.
2C2H6(g) + 70215)
True
4CO2(g) + 6H20(3)
False
Answer:
false
Explanation:
i did it